In general, an electronic hydraulic brake apparatus detects pedal pressure caused by a driver by using a sensor, and then adjusts braking pressure applied to each wheel by using a hydraulic modulator.
The electronic hydraulic brake apparatus is provided with a sensor which detects a stroke of a pedal so as to recognize braking pressure desired by the driver, and a pedal simulator which allows the driver to feel pedal pressure that the driver may feel from a general hydraulic brake apparatus.
In a normal state, when the driver presses a brake pedal, pressure is generated by a back-up master cylinder, and the pressure generated by the back-up master cylinder is transmitted to the pedal simulator, thereby allowing the driver to feel reaction force.
A control unit determines braking force desired by the driver by using a pedal stroke sensor, a pressure sensor or the like, and operates a main master cylinder to cause a wheel brake to generate braking force.